Panoramic fireplace: Camina or Brunner - or something completely different?

Framework conditions: We would like to install a fireplace in our new living/dining/kitchen area (construction starting in April, approx. 60sqm) and have been considering a panoramic fireplace that can be viewed from the living area and where the flames can also still be seen from the dining area. As is the case now, our planned house will have underfloor heating. In our current apartment, we had a Swedish stove in the living room that saved us a lot of money on heating in winter, but it does not retain heat for very long, which is currently somewhat of a drawback for us. The chimney behind it has two flues, is positioned in front of a load-bearing wall, and has a width of about 83cm.

The offer - three variants (each with fire table/bench):

[*]~ €7,500: Camina S12 tall in white with storage concrete, width 70cm (plus bench)
[*]~ €8,500-9,000: Camina S12 tall, plastered and adapted to the rear wall so that no width differences are visible
[*]~ €10,000: Brunner 42/42/42/42 completely with fireclay bricks up to the top, plastered and custom-fitted to the wall

The stove builder recommended variant 3 to us because with fireclay it has better storage capacities and, according to his experience, the seal on the sliding door as well as the glass rinse system are more sophisticated and durable. The other variants, however, are not significantly inferior in quality. At least nominally, the Camina has a significantly lower heating output with 4kW than the Brunner (8kW), which is quite common with storage stoves.

How do you see it – is anyone in a similar situation or has installed one of the stoves and can give us a tip? What are your experiences with fireclay compared to storage concrete?

I can only post experiences in the fall. In any case, we took this one from Brunner. The insert has the same dimensions as in your offer, but we are paying 17K including storage stones, dark firebox, USA, and wood storage as shown. Air supply through the outer wall.

I have to say upfront, I am not an expert, but yesterday we had a discussion with my uncle who has been a stove builder for 25 years. A panoramic fireplace is significantly less suitable for heating than one with two-sided glazing. The panoramic glazing will be 95% soot-covered, whereas with two-sided glazing there are systems that integrate ventilation from below between the fire and the glass, which significantly reduces soot formation. Just a note

Pay attention to the lowest possible air flow. Especially with more than one panel, it quickly gets uncomfortably warm in the room.

Brunner is basically the Mercedes, you can't go wrong with that. I have had a Schmid boiler insert with water circulation for a year now, that is the company behind camina. So far I am very satisfied, the glass cleaning works, little ash and otherwise solid. Even without burn control it runs great. However, on a Brunner BHZ

I am also satisfied with the Brunner unit – but I have no comparison. The glass usually only gets black quickly if you use poor fuel.

We don't have the problem of the rooms heating up too fast. Rather the opposite – sometimes I wish the thing gave off more heat. But that is due to the open spaces and certainly not the case for many others.

10k for a stove is okay in my opinion. I chose Brunner because of the good reputation and positive reviews online and would have been willing to spend 1k more for it.

The panoramic glazing will be 95% covered in soot

The sooting has less to do with the panoramic glazing itself, but rather with the type of firing. Soot usually forms when there is not enough oxygen available and the fuel burns incompletely, right? Our chimney builder here in the area often works as an expert witness for the courts. The issue of soot on glass is apparently a recurring topic. At least with the ring gap chimney, black glass often results because the chimney does not match the local conditions and the system. Ring gap chimneys apparently have more problems because the hot exhaust gases rising upwards in the outer ring eventually warm the cool fresh air, and the chimney effect is weakened due to the reduced temperature difference. The result is that oxygen does not flow quickly enough into the combustion chamber to supply the entire space with oxygen. Instead, some is immediately directed back into the flue. There is a lack of oxygen for clean combustion, and the end result is black glass. This only has limited connection to the insert itself, but rather to proper design. And the "glass cleaning air curtain" does not work effectively in these cases because the "air curtain" that forms in front of the glass does not develop at all due to the too slow inflow of air. They apparently had to demonstrate this effect of the ring gap in a test using tracer gases. So this seems not to be just theory. A second, popular cause for black glass can also be oversized chimney systems. The generated heat has to go somewhere, and if the surrounding room is too small, it quickly becomes too warm. What does a chimney owner do then? They throttle, i.e., reduce the oxygen supply with the same physical mechanism and result as above. Actually, a chimney builder should know this... When I look at how "professionally" our chimney was initially planned, I am not really surprised anymore. I visited a total of 3 stove builders; the first two neither cared about the location of the house nor the room sizes, but "planned" a stylish piece of furniture – independent of room geometry and the heating outputs of the inserts, we were offered inserts based on appearance... Before starting the planning, our chimney builder first informed us about the basic input parameters for planning and then started working with us. To approve the ring gap planned by the architect, he first obtained the air pressure conditions at the construction site and then calculated whether the chosen chimney would even be suitable. As an engineer, I somehow appreciate this approach more than guesswork based on a rough estimate and appearance.